1. Field of the Invention
The invention relates to a load-bearing frame for a chair, in particular for an office chair which can be adjusted in terms of its height and inclination, comprising a standing column, a load-bearing and pivoting device arranged thereon, a seat carrier and a backrest carrier, the seat carrier and the backrest carrier being mounted on the load-bearing and pivoting device by means of struts arranged on the knee side and backrest side of a spindle body, and it being possible to pivot the said carriers backwards about the horizontal axis of the load-bearing and pivoting device against the restoring force at least of a first spring element, and to fix them in any position, and release them again by a second spring element arranged parallel or transversely to the axis.
2. Description of the Prior Art
EP-A 0 485 868 discloses an office chair which can be adjusted in terms of its height and inclination and comprises a load-bearing frame essentially constituted by a seat carrier, a backrest carrier and a first and a second guiding rod arrangement, which frame is mounted on a load-bearing body arranged and fastened on a standing column and, together with the seat carrier and backrest carrier, can be inclined backwards against the restoring force of a rotation and torsion bar, and can be fixed in any position by a pneumatic spring which can be locked and released again.
The object of the invention is to design and improve a chair of the generic type such that, while maintaining the ergonomic requirements dependent on the user, no transverse forces are transmitted to the spring element compensating for the backwards and forwards pivoting movement and, in addition, an effortless, synchronised movement progression is ensured.